Table 6.
The relationship between sleep time and mental health in participants aged 13–15 years.
| Sleep Time (h/day) | p for Trend a | |||||
|---|---|---|---|---|---|---|
| <6 | 6 | 7 | 8 | ≥9 | ||
| Participants (n) | 160 | 675 | 932 | 557 | 115 | |
| SDQ ≥16 (n) | 39 | 109 | 136 | 95 | 36 | |
| Crude RR | 1.67 (1.22−2.29) | 1.11 (0.88−1.40) | 1.00 (reference) | 1.17 (0.92−1.49) | 2.15 (1.57−2.93) | 0.580 |
| Age-sex-adjusted RR b | 1.67 (1.22−2.30) | 1.11 (0.88−1.40) | 1.00 (reference) | 1.17 (0.92−1.49) | 2.14 (1.56−2.94) | 0.580 |
| Multivariate RR c | 1.13 (0.82−1.56) | 0.97 (0.77−1.22) | 1.00 (reference) | 1.19 (0.93−1.51) | 2.04 (1.49−2.77) | 0.015 |
RR, risk ratio; a p for trend values were calculated with sleep time as a continuous variable; b Adjusted for sex (male or female) and age (13 years old, 14 years old, or 15 years old); c Adjusted for age and sex plus current state of health (very good or good, normal, or poor or very poor), adequate sleep (adequate, slightly inadequate, or inadequate), evacuation (inside Fukushima or to other prefectures), tsunami experience (yes or no), nuclear reactor accident experience (yes or no), respondent of Q1–6 (participant or proxy), respondent of other questions (mother, father, or other).